Two New Serranid Fishes of the Genus Pseudanthias from the Western Indian Ocean
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RANDALL New Pseudanthias species 79 Two New Serranid Fishes of the Genus Pseudanthias from the Western Indian Ocean John E. Randall Bishop Museum, 1525 Bernice St., Honolulu, HI 96817-2704, USA e-mail: [email protected] Received 8 October 2010; accepted 13 March 2011 ABSTRACT. Pseudanthias bimarginatus, described RÉSUMÉ. L’espèce Pseudanthias birginatus, décrite from five specimens collected in 48 m at the à partir de 5 échantillons collectionnés à 48 m à Maldive Islands, is characterized by 16 dorsal Maldives, possède les caractéristiques suivantes : soft rays, 16 or 17 pectoral rays, 42–43 lateral-line 16 douces raies dorsales, 16 ou 17 raies pectorales, scales, 10–11 + 22–25 gill rakers, slender body 42–43 écailles sur les lignes latérales, corps mince, (depth 3.0–3.3 in SL), thickened front of upper lip, le devant de la lèvre supérieure incliné, papilles no serrae on subopercle or interopercle, orbital orbitales, pas de colonnes dorsales rallongées, papillae, no elongate dorsal spines, lunate caudal nageoire caudale semi-lunaire, deux petites fin, two narrow magenta bands dorsally on head bandes dorsales magenta sur la tête joignant le that join across front of snout and medially on museau frontal ; la nageoire caudale du male est nape; caudal fin of male red grading to yellow rouge et jaunit petit à petit, avec des marges bleue- posteriorly, with very broad, lavender-blue, upper lavande supérieures et inferieures très larges. and lower margins. P. unimarginatus, represented L’espèce P. unimarginatus, représentée par un by one 52.6-mm male specimen collected in 53 m at échantillon de 52.6 mm pris à 53 m à l’Ile Maurice Mauritius, shares the morphological characters of possède les caractéristiques morphologiques de P. P. bimarginatus except for having 18 pectoral rays bimarginatus, à l’exception du fait de posséder 18 and 9 + 25 gill rakers; it differs in colour principally raies pectorales; la différence réside dans la couleur in having a yellow caudal fin with only a broad également en ceci qu’il possède une nageoire upper lavender-blue margin and a submarginal caudale jaune avec une seule marge supérieure red band. Both species are close relatives of P. bleu-lavande et une bande sous-marginale rouge. parvirostris from Indonesia, Solomon Islands, and Toutes les deux espèces sont proches parentes de Palau, which differs in having more numerous P. parvirostris d’Indonésie, des Iles Salomon, et preopercular serrae, no serrae on subopercle and Palau, avec la différence que ce dernier possède interopercle, modally fewer gill-raker, and in plus des serrae pré-operculaires et une coloration caudal-fin colouration. de nageoire caudale différente. KEY WORDS: taxonomy, Serranidae, Pseudanthias, new species, Western Indian Ocean INTRODUCTION They listed the 65 nominal species then placed in the genus Pseudanthias, of which 49 were regarded The Indo-Pacific fish genus Pseudanthias contains as valid. Two new species of Pseudanthias are small, colourful, coral-reef fishes of the family described in the present paper, one represented Serranidae, subfamily Anthiinae, that are usually by five specimens collected in 48 m in the Maldive found in aggregations. They feed on zooplankton Islands in 1988 and misidentified by Randall well above the substratum, but quickly take shelter & Anderson (1993) as P. parvirostris Randall & in the reef when threatened. Males are larger, Lubbock, and the other by a single male specimen generally more colourful, and maintain a harem. If taken in 53 m at Mauritius in 1980. Regrettably, no a male is removed, the dominant female changes additional specimens are known of either species. in time to a male and assumes control of the harem (Shapiro, 1981). Bleeker (1871; 1873) described the genus MATERIALS AND METHODS Pseudanthias for six species. Boulenger (1895), however, regarded it as a synonym of Anthias, and Type specimens have been deposited in the he was followed until Katayama in Masuda et al. Bernice P. Bishop Museum, Honolulu (BPBM); the (1984) and Katayama & Amaoka (1986) recognized South African Institute for Aquatic Biodiversity, Pseudanthias as a valid genus. Grahamstown (SAIAB); and the U.S. National Randall & Pyle (2001) described four new Museum of Natural History, Washington, D.C. species of Pseudanthias from the South Pacific. (USNM). 15 April 2011 80 RANDALL New Pseudanthias species Lengths given for specimens are standard limb count is given first, and the raker at the angle length (SL), the straight-line distance from the is included in the lower-limb count. median anterior point of the upper lip to the base of the caudal fin (posterior end of hypural plate). Pseudanthias bimarginatus sp. nov. Head length (HL) is measured from the same Pl. 1 A-C; Tables 1, 3 anterior point to the posterior end of the opercular membrane, and snout length from the same point Pseudanthias parvirostris (non Randall & Lubbock), to the fleshy edge of the orbit. Body depth is the Randall & Anderson 1993: 14 (Maldive Islands). greatest depth from the base of the dorsal spines; Pseudanthias parvirostris (non Randall & Lubbock), body width is the greatest width measured just Kuiter 1998: 76, upper figs (Maldive). posterior to the gill opening. Orbit diameter is the greatest fleshy diameter, and interorbital width the Holotype. BPBM 34697, male, 48.0 mm, Republic least bony width. Caudal-peduncle depth is the of Maldives, North Malé Atoll, lagoon, east side of least depth; caudal-peduncle length is measured Furana Island, steep rocky bottom, 48 m, rotenone, horizontally from the rear base of the anal fin to the J. E. Randall, R. C. Anderson & M. S. Adam, 29 caudal-fin base. Predorsal, preanal, and prepelvic October 1988. lengths are taken from the front of the upper lip to the origin of the respective fins. Lengths of fin Paratypes. BPBM 41006, 33.9 mm; SAIAB 86490, spines and soft rays are measured to their extreme 2: 38.8–43.1 mm; USNM 398058, 36.8 mm, all with base. same data as holotype. Proportional measurements are given in the tables as a percentage of the standard length. DIAGNOSIS. Dorsal-fin rays X,16; anal-fin rays III, Proportions in the text are ratios rounded to the 7; pectoral-fin rays 16–17 (usually 17); lateral-line nearest 0.05. Lateral-line scale counts include all scales 42–43; gill rakers 10–11 + 22–24; body depth pored scales. Gill-raker counts were made on the 3.0–3.3 in SL; head length 2.9–3.1 in SL; papillae first gill arch and include rudiments; the upper- on posterior edge of orbit; no serrae on edge of subopercle or interopercle; snout length 3.75–4.45 Table 1. Proportional measurements of type specimens of Pseudanthias bimarginatus as percentages of the standard length Holotype Paratypes BPBM BPBM USNM SAIAB SAIAB 34697 41006 398058 86490 86490 Sex male female female female male Standard Length (mm) 48.0 33.9 36.8 38.8 43.1 Body depth 30.2 33.0 32.9 30.8 30.3 Body width 15.0 17.7 15.0 17.2 16.6 Head length 32.2 33.3 34.4 34.1 32.7 Snout length 7.5 8.9 8.2 7.7 8.3 Orbit diameter 9.1 11.6 11.1 10.4 9.7 Interorbital width 8.6 9.7 9.7 9.2 8.8 Upper-jaw length 16.6 16.4 16.6 16.7 16.5 Caudal-peduncle depth 13.9 15.4 15.9 15.1 15.5 Caudal-peduncle length 20.6 20.0 20.7 18.5 18.5 Predorsal length 32.7 34.9 33.8 34.0 33.3 Preanal length 59.3 60.4 60.0 60.2 59.5 Prepelvic length 33.4 34.1 34.2 33.8 34.0 Dorsal-fin base 54.3 53.9 53.7 53.9 54.1 First dorsal spine 5.8 5.6 5.6 5.4 6.0 Third dorsal spine 10.6 12.9 12.8 12.4 12.2 Tenth dorsal spine 11.6 14.1 13.9 12.6 13.4 Longest dorsal ray broken 20.9 19.5 18.5 18.9 Anal-fin base 21.2 22.5 21.5 22.2 20.8 First anal spine 8.7 9.2 9.4 9.1 8.9 Second anal spine 11.8 12.1 13.3 12.8 11.9 Third anal spine 12.9 14.6 broken 14.5 13.5 Longest anal ray broken 24.1 24.4 22.7 25.6 Caudal-fin length 41.7 40.9 40.5 39.4 42.1 Caudal concavity 26.3 27.2 24.7 24.3 27.6 Pectoral-fin length 31.7 34.9 31.4 32.2 33.0 Pelvic spine length 17.1 19.5 16.6 18.6 16.5 Pelvic-fin length 37.5 33.2 33.5 27.7 30.1 Smithiana Bulletin 13: 79 - 87 RANDALL New Pseudanthias species 81 in HL; front of upper lip thickened and moderately snout at base of upper lip, the tubule longest protuberant; bony interorbital width 3.45–3.75 in dorsoposteriorly; posterior nostril obliquely HL; fourth to tenth dorsal spines subequal, 2.15– dorsoposterior to anterior nostril, about a nostril 2.8 in HL; caudal fin lunate, 2.4-2.55 in SL; males diameter before fleshy edge of orbit, with a well- lavender-pink, the head yellow dorsally with developed narrow rim, except posteriorly. narrow magenta bands; caudal fin red with broad, Opercle with three flat spines, the middle at level upper and lower lavender-blue margins; females of centre of eye, clearly largest and most posterior, mainly yellow with flecks of magenta, the head closer to lower than upper spine; upper opercular with the same magenta bands as male; fins mainly spine nearly covered by scales; posterior margin yellow with a narrow magenta margin.